Method of treating ores.



HARRY LOUIS FRIBERGER, .OF EUREKA, KANSAS, ASSIGNQR F THREE-TENTI-IS '10 VICTOR C. JOSLYN AND THREE-TENTHS T0 CORNELIUS HORATIUS KELLER, BOTH O F EL PASO, TEXAS.

Specification of Letters Patent.

METHOD or TREATING onus.

Patented May a, 1199M.

. No Drawing. Application filed June 3, 1916, Serial No. 101,564. Renewed March 20, 1917. Serial No.

To all whom it may concern.

Be it known that I, HARRY Louis FRI- BERGER, a citizen of the United States, residing at Eureka, in the county ofGreenWood and State of Kansas, have invented certain new and useful Improvements in Methods of Treating Ores, of which the following is a specification.

The present invention relates to a method stituents of said ore. This process, so far as I have been able to ascertain, hasjnot heretofore been successfully applied to cyanid solutions, and in those places'where this has been attempted, satisfactory results were not obtained. i

In the treatment of ores by cyanid solution various bases in the ores give considerable trouble destroying-cyanid and interfer ing with the gold and silver recovery.

- These bases being generally referred to as cyanicids.

vIn the proposed invention I remove by flotation these cyanicids such as copper, iron, I

lead, antimony, etc., as well as a portion of the precious metals, gold and silver before the cyanicids have a chance to exerciseany deteriorating influence upon the cyanid so lution.

I In starting the process I start with cyanid solution of the ordinary strength, as used in the cyanidation of gold and silver ores, which strength .will of course, depend more or less upon the amountof gold and silver or both in the ore under treatment, and also upon the nature of the gangue material and y other factors. In the ordinary cyanid treat-- ment this cyanid solution generally carries a protective alkali.

To the ore ground to the necessary fineness and diluted with the cyanid solution to the proper consistency I then add sufficient of the frothingmedium hereinafterdescribed to make upon agitation. a metal-bearing froth. The apparatus employed may be any of the conventional types of flotation machinery such as the Callow cell, mineral separation orsplash system. The resultant concentrate may then be marketed or treated. The tailings if necessary given a further treatment and the values contained in the solution recovered by any of the ordinary methods.

- In all other methods of flotation where further treatment of 'tailings becomes necessary to recover the gold and silver by cya- "nidation the following tedious and'expen sive system'is employed. The tailings are dewatere'd as close as any of the modern methods of filtration will permit and the remaining moisture contained varying from 30% to 50% must then be made up to the working strength with fresh cyanid and sufiicient more cyanid solution added to give it the proper moisture ratio.-

In preparing frothing medium I dissolve I a resinous substance, such as ordinary rosin (anhydrid of abietic acid) in alcohol, the amount of rosin used being between 25 and 50% ofthe amount of alcohol'used. I then add to this solution an amount of alkaline hydrate,'particularly caustic soda, preferably just enough of this being employed to neutralize the entire amount of rosin used without leaving any material excess of alkali.

From this liquid thereby produced I distil off all or substantially all the alcohol for re-use. While this alcohol so recovered may not be entirely pure the impurities are such as will not-injuriously affect the same for re-use, in the process. This will leave a liquid,semi-liquid or solid residue according This 10 pounds of commercial rosin are dis solved in 25 pounds of alcohol (about 90% strength) to which a suflicient amount of caustic soda solution of about 40% strength is added to just neutralize the material. The residue from this liquor after distillation is added to about 5 gallons of water.

A mill such as a ball, Chilian or stamp grinds an ore to necessary fineness with about 15% Ken. (more or less) solution, a convenient moisture ratio being about 3.5 parts of solution to 1 part of ore.

Before this enters the flotation cell a small quantity of the frothing solution is continuously dripping into this pulp so that about one half pint of the frothing liquid Wouldbe added to each ton of dry ore contained in the pulp. Then by the agitation in the cell a metal bearing froth rises to the surface carrying what 15 generally termed concentrates and overflows or is scraped off. These concentrates upon being dewatered are ready for marketing.

The tailings or balance of the pulp is then settled or filtered and the liquid recovered is treated byzinc to recover the gold and silver in solution and then returned to the head of the mill to be used again as a crushing solution thereby conserving not alonethe cyanidin solution but also all the froth.) ing solution mixed with it.

It being-foundthat 90% of the gold and 85% of the silver is a fair recovery and often 95% of the copper and as high as 80% of the lead have been floated. By'this novel processI am enabled to obtain very excellent results upon very low grade materlal such as ores containing very small amounts .01: the precious metals where the gold and silver alone cannot be commercially recovered by cyanidation due to the cyanicids and where it is impossible-to recover them by any other method of flotation.

Also there are-millions of'tons 'of tailings from cyanid plants that can be retreated with a profit by this process that cannot be rents of air of suflicient volume to float any A portion of the values amenable, to flotation. 2. In the cyanidation of precious metal ores the step of frothingsome constituents of the ore with subdivided currents of air while the saidore is mixed with a solution containing dissolved cyanid, and an alkali resinate.

3. The combined process of cyanidation and flotation of previous metals bearing ores which comprises dissolving a resinous substance in alcohol, adding an alkali to substantially complete neutralization, distilling ofl' superfluous solvent and incorporating the resultant residue with a cyanid[ solution,

treating the ore in said liquid with sub-divided air to float some constituents of the ore and thereby separate said constituents and after filtration removing the precious metals from thesaid solution.

4. A process of treating ores which comprises floating the material containing metal in a' cyanid solution by introducing divided air currents, into a body of cyanid solution containing the finely divided ore, while in the presence of a material capable ofincreasing the affinity of the metal containing particles for the air bubbles.

In testimony whereof I aflix my signature in presence of two witnesses.

HARRY LOUIS FRIBERGER. Witnesses: H. E. CLARK, W. DRABRINK. 

